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Old 11-26-2018, 11:16 AM
  #1081  
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Originally Posted by idbdoug
Looking for smallest, cheapest personal pc device to use the the data logging feature! Can someone send me a link on the pc requirements for data logging or tell me which devices are best? This laptop/ tablet will only be used for this activity
thanks
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This is what I got for more or less the same purpose, but at the time I got it they were $170. Itís more than enough to look at the data logs
Acer aspire one Acer aspire one
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Old 11-26-2018, 11:17 AM
  #1082  
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Originally Posted by MaxRain
Looking for some feedback on the following...

Just finished making my home made dyno, similar design to a mini pro and using simple dyno to record the results.. The arduino samples at just over 200hz.
Gear ratio is 2:1, inertia of the flywheel is 410kg mm^2.

When reviewing the graph, peak power is generated just under 10k RPM..

comparing the dyno results to a data logger file, would it be better to set timing to have peak power kick in after the avg rpm in the mid part of the track or would it be better to focus on efficiency (11k-15k RPM) ?


What motor, and are you racing or just looking for straight line speed?
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Old 11-26-2018, 07:02 PM
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Originally Posted by geeunit1014


What motor, and are you racing or just looking for straight line speed?
Current motor is surpass VS4 17.5 for touring stock, and racing

Last edited by MaxRain; 11-26-2018 at 07:53 PM.
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Old 11-26-2018, 07:52 PM
  #1084  
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Here is a pivot table of the CSV file from my last race. It shows where most of the time was spent on the track.
Based on the dyno result above, the window where max power is generated is 7500 - 11500 rpm.
The window for highest efficiency is in the 10,000 - 15000 RPM range.

Would it be better to spend more time of the track in the max power or the high efficiency range?

link for the video. I am driver #2 from the right, burgundy colour shirt.

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Old 11-27-2018, 08:15 AM
  #1085  
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Originally Posted by MaxRain
Here is a pivot table of the CSV file from my last race. It shows where most of the time was spent on the track.
Based on the dyno result above, the window where max power is generated is 7500 - 11500 rpm.
The window for highest efficiency is in the 10,000 - 15000 RPM range.

Would it be better to spend more time of the track in the max power or the high efficiency range?

link for the video. I am driver #2 from the right, burgundy colour shirt.
Touring Stock B main

​​​​​​Very good.... I see you spent about 30% of the time in the 7000-11000 rpm range. Maybe increasing that percentage in that range will decrease the other percentages of time spent in other ranges, but I think the analysis of multiple runs might shed a bit more light on the matter....
​​​​​​
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Old 11-27-2018, 06:30 PM
  #1086  
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Originally Posted by MaxRain
Looking for some feedback on the following...

Just finished making my home made dyno, similar design to a mini pro and using simple dyno to record the results.. The arduino samples at just over 200hz.
Gear ratio is 2:1, inertia of the flywheel is 410kg mm^2.

When reviewing the graph, peak power is generated just under 10k RPM..

comparing the dyno results to a data logger file, would it be better to set timing to have peak power kick in after the avg rpm in the mid part of the track or would it be better to focus on efficiency (11k-15k RPM) ?


Well, the answer would typically be "gear it so you get the most area under the curve". If you're not running out of power, you should be gearing for maximum power, instead of maximum efficency.

I love that you built a dyno. I think I know the dyno software you're running, do you have your adruino details up anywhere?
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Old 11-28-2018, 09:55 PM
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Originally Posted by Nerobro
Well, the answer would typically be "gear it so you get the most area under the curve". If you're not running out of power, you should be gearing for maximum power, instead of maximum efficency.

I love that you built a dyno. I think I know the dyno software you're running, do you have your adruino details up anywhere?
The name of the software is simple dyno. The guy who coded it really knew what he was doing and did an excellent job on it.

I will have to run more dyno pulls to compare against other race runs from the past..

In conversation with some other drivers at the track, some say to gear so that more of the power is used sooner. For example to flat line the datalogger RPM in the mid part of the straight. I think this approach could be over rev the motor and may not be a good approach. Thoughts?
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Old 11-29-2018, 08:46 AM
  #1088  
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Gearing lower might over rev the motor and not give lower laptimes. I always preferred gearing one tooth higher than the gearing that obviously overgeared the motor, and then put the esc(lowest frequency settings) minimum drive all the way up in addition to raising the radio throttle trim up a bit(88% up)... This seemed to never allow the motor to go down to the low revs when I was off the throttle and reduced abrupt acceleration alot, making the car smoother while carrying more corner speed: my laptimes did go down and my motor ran much cooler. The only downside is that I had to be stay on the brakes to stop the car from moving at the start line....
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Old 11-29-2018, 07:25 PM
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Originally Posted by bertrandsv87
Gearing lower might over rev the motor and not give lower laptimes. I always preferred gearing one tooth higher than the gearing that obviously overgeared the motor, and then put the esc(lowest frequency settings) minimum drive all the way up in addition to raising the radio throttle trim up a bit(88% up)... This seemed to never allow the motor to go down to the low revs when I was off the throttle and reduced abrupt acceleration alot, making the car smoother while carrying more corner speed: my laptimes did go down and my motor ran much cooler. The only downside is that I had to be stay on the brakes to stop the car from moving at the start line....
Ah, I understand this approach and will try the settings suggested.. In addition you got me thinking about what I noticed recently. After calibrating the ESC to a new radio recently purchased (Sanwa MTS), the telemetry graph for throttle show that the neutral signal is below zero, at approximately -30 points. and then full throttle is above 60 something. My first thought was that it is not calibrating correctly as my previous radio (Futaba 3pk) did not do this but was when I adjusted the trim settings on the radio, similar to what you did above. The result was that Neutral throttle was near zero on the graph with the Futaba.
After running the car and reseting/recalibrating between heats, the result was the same, neutral at -30, full throttle at 60. Then thought to check Randy's video on youtube with instructions on how to calibrate, and he mentions that as long as all the bars are flashing when full throttle and brake is squeezed, then I should be ok. Is this correct? or should I adjust the trim to ensure that neutral on the radio registers at zero or just above as you have done to avoid being in too low of an rpm mid corner.

I am also thinking that push control would be better to play with to create the same effect as you describe above.

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Old 11-29-2018, 10:53 PM
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I must say I don't know what push control does, but if your neutral is around -30 then make sure you have full brakes(all bars flashing) or at least enough brake travel to brake safely. Your throttle will have a wider range and the effect will be felt probably around 58% throttle trim... Someone also explained to me that putting that constant throttle input reduces the inductance effect caused by constantly going neutral/full throttle then neutral/brake and back to neutral/full throttle. Instead you would only get part throttle to full throttle then part throttle/brake and part throttle to full throttle again: current would always flow through the circuits, avoiding any inductance(not caused by frequency) around neutral/throttle and neutral/brake...Some fast racers are able to keep their trigger finger at part throttle all the time for a similar effect, but that takes a whole lot of practice/talent to master.....

Last edited by bertrandsv87; 11-29-2018 at 11:11 PM.
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Old 11-30-2018, 08:55 AM
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Originally Posted by MaxRain
Ah, I understand this approach and will try the settings suggested.. In addition you got me thinking about what I noticed recently. After calibrating the ESC to a new radio recently purchased (Sanwa MTS), the telemetry graph for throttle show that the neutral signal is below zero, at approximately -30 points. and then full throttle is above 60 something. My first thought was that it is not calibrating correctly as my previous radio (Futaba 3pk) did not do this but was when I adjusted the trim settings on the radio, similar to what you did above. The result was that Neutral throttle was near zero on the graph with the Futaba.
After running the car and reseting/recalibrating between heats, the result was the same, neutral at -30, full throttle at 60. Then thought to check Randy's video on youtube with instructions on how to calibrate, and he mentions that as long as all the bars are flashing when full throttle and brake is squeezed, then I should be ok. Is this correct? or should I adjust the trim to ensure that neutral on the radio registers at zero or just above as you have done to avoid being in too low of an rpm mid corner.

I am also thinking that push control would be better to play with to create the same effect as you describe above.
It doesn't matter what the neutral signal is, as long as the ESC is calibrated to the radio signal you can make the neutral whatever you want. The shown settings on the radio don't matter, you can reverse the signal and still get proper ESC operation when doing the "one-touch" calibration on the ESC or the Tekin equivalent. Sanwa radios have a 70/30 split on the trigger, where 70% of the total throw is throttle, 30% brake, so I would think that was the reason the telemetry was reading "neutral = -30", it's not something that needs fixing.

Tuning in "creep" as they used to call it, where in the neutral point on the radio trigger is actually a little bit of throttle, is a tuning tool, not magic. I don't know the exact method of how "push control" works, but from the video Randy Pike made "push control" is effectively anti-drag-brake, and from what I have seen it is effectively "creep" that is determined by how long you spent at WOT, and it is slowly turned down by the ESC, letting off that last bit of throttle slowly. I've seen a 1/12 car coast all the way down the back straight on "push control" with a Tekin ESC. If you have it, it very well may be worth experimenting with.
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Old 11-30-2018, 09:24 AM
  #1092  
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Originally Posted by MaxRain
Here is a pivot table of the CSV file from my last race. It shows where most of the time was spent on the track.

Based on the dyno result above, the window where max power is generated is 7500 - 11500 rpm.

The window for highest efficiency is in the 10,000 - 15000 RPM range.


Would it be better to spend more time of the track in the max power or the high efficiency range?

Hey Gord, a couple more things for you to consider on your question about max power vs high efficiency. When your motor was in it's most common RPM (3000-3999 as per your CSV), what was the throttle input at that time? I suspect you would get closer to an answer for your question, if you could figure how much time you spent with the throttle 100% applied in that specific RPM range (or any of the ranges for that matter)


I am assuming your dyno plot was logged with 100% throttle application, and therefore would only make the max power and high efficiency ranges applicable to a situation where you drove with the throttle at 100%. Any time you're coasting, partial throttle application, or decelerating through an RPM range is not applicable to your dyno plot... so you could assume that some portion of the data logged isn't valid data anyway. (unless your CSV is filtered for 100% throttle application only? - Sorry I'm not familiar with how you recorded it)

But for what it's worth, because we race on a track that demands constant re-acceleration for the cars, you would want to spend that acceleration time in the max power condition (who would want to accelerate slowly? haha). If we raced on an oval, where you can maintain a fairly constant speed, re-acceleration isn't as big of a factor, so higher efficiency would be more desirable.

Just some info to consider... we should have a BS about it at the track later.


Steve

Last edited by nizmogizmo; 11-30-2018 at 09:46 AM. Reason: more thoughts on the matter.
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Old 11-30-2018, 12:51 PM
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It seems that the simplest way to put it is that every mode has a curve to control it, whether it's throttle, brakes, drag brake, creep,etc,... That will be very beneficial for smoothness and potentially reduce laptimes versus the old style linear esc's....
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Old 12-01-2018, 09:51 AM
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Originally Posted by DesertRat
It doesn't matter what the neutral signal is, as long as the ESC is calibrated to the radio signal you can make the neutral whatever you want. The shown settings on the radio don't matter, you can reverse the signal and still get proper ESC operation when doing the "one-touch" calibration on the ESC or the Tekin equivalent. Sanwa radios have a 70/30 split on the trigger, where 70% of the total throw is throttle, 30% brake, so I would think that was the reason the telemetry was reading "neutral = -30", it's not something that needs fixing.

Tuning in "creep" as they used to call it, where in the neutral point on the radio trigger is actually a little bit of throttle, is a tuning tool, not magic. I don't know the exact method of how "push control" works, but from the video Randy Pike made "push control" is effectively anti-drag-brake, and from what I have seen it is effectively "creep" that is determined by how long you spent at WOT, and it is slowly turned down by the ESC, letting off that last bit of throttle slowly. I've seen a 1/12 car coast all the way down the back straight on "push control" with a Tekin ESC. If you have it, it very well may be worth experimenting with.
After further testing, when squeezing the radio at full throttle/brake, the ESC LED's light up to full of each and flicker. No longer concerned.
At my last outing at the track, started to play with push control, and set it to setting #3 see what it felt like. After the first round of testing I felt that it coasted the car a little more than expected, which also influenced my braking points. I found that I had to change them to prevent overshooting corners. After the run, I felt that the push control creates the creep and can be adjusted to suit your driving style. Thinking about Randy's statement on push control that "less is more" holds true, as the next run I adjusted the value to 2 and noticed a difference again. Going to test higher settings 4 and 5 to see how it affects corner speed and I hope to find what settings works best for me.

Will be comparing CSV results of each test to also see how it is affecting the motor RPM's as well.

Steve, your comment got me thinking and we will have to discuss more as I think there is something we can always learn from a csv file. This reminds me of the slogan "smaller", "smarter", "FASTER"!!!

Gordon
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Old 12-01-2018, 01:13 PM
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Nice work. I'm very interested in your push control results.
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